Robot and multiple robot control method

Abstract

When braking of a motion of a part of a first robot is assumed to be started at points in time, a first stop position of the first robot part is estimated at each point in time. When braking of a motion of a part of a second robot is assumed to be started at the points in time, an estimated second stop position of the second robot part is obtained at each point in time. When it is determined that the first stop position of the first robot part at one of the points in time and either the actual position or the second stop position of the second robot part for each interval at the one of the points in time are contained in the shared workspace, the first robot part is braked.

1. A multiple robot control method for a plurality of robots each with a movable part, in which the plurality of robots share a workspace and operate the movable parts, respectively, the method comprising:
 when braking of a motion of the operated movable part of a first robot in the plurality of robots is assumed to be started at plurality of points in time, estimating a first stop position of the movable part of the first robot at each point in time; 
 when braking of a motion of the operated movable part of a second robot in the plurality of robots is assumed to be started at the plurality of points in time, obtaining an estimated second stop position of the movable part of the second robot at each point in time; 
 determining, at at least one of the points in time, whether the estimated first stop position of the movable part of the first robot and at least one of an actual position and the obtained second stop position of the movable part of the second robot are contained in the shared workspace; and 
 braking the movable part of the first robot when it is determined that the estimated first stop position of the movable part of the first robot at the at least one of the points in time and at least one of the actual position and the obtained second stop position of the movable part of the second robot at the at least one of the points in time are contained in the shared workspace. 
 
   
   
     2. A multiple robot control method according to  claim 1 , further comprising:
 determining whether the actual position and the obtained second stop position of the movable part of the second robot are not contained in the shared workspace at a point in time after the braking; and 
 when it is determined that the actual position and the obtained second stop position of the movable part of the second robot are not contained in the shared workspace at the point in time after the braking, continuing the motion of the movable part of the first robot from where the motion of the movable part of the first robot has been stopped. 
 
   
   
     3. A robot communicable with another robot and having a workspace shared with another robot, the robot comprising:
 a robot body having a movable part; 
 an operating unit configured to operate the movable part; 
 is a first estimating unit configured to estimate, when braking of a motion of the operated movable part is assumed to be started at a plurality of points in time, a first stop position of the movable part at each point in time; 
 an accessing unit configured to access another robot to:
 obtain, when braking of a motion of an operated movable part of another robot is assumed to be started at the plurality of points in time, an estimated second stop position of the movable part of another robot at each point in time, and 
 obtain an actual position of the operated movable part of another robot at each point in time; 
 
 a first determining unit configured to determine, at least one of the points in time, whether the estimated first stop position of the movable part and at least one of the actual position and the obtained second stop position of the movable part of another robot are contained in the shared workspace; and 
 a braking unit configured to brake the movable part when it is determined that the estimated first stop position of the movable part at the at least one of the points in time and at least one of the actual position and the obtained second stop position of the movable part of another robot at the at least one of the points in time are contained in the shared workspace. 
 
   
   
     4. A multiple robot control method according to  claim 3 , further comprising:
 a second determining unit configured to determine whether the actual position and the obtained second stop position of the movable part of the second robot are not contained in the shared workspace at a point in time after the braking of the braking unit; and 
 when it is determined that the actual position and the obtained second stop position of the movable part of the second robot are not contained in the shared workspace at the point in time after the braking of the braking unit, a continuing unit configured to continue the motion of the movable part of the first robot from where the motion of the movable part of the first robot has been stopped. 
 
   
   
     5. A robot controller for a robot communicable with another robot and having a movable part and a workspace shared with another robot, in which the robot controller is operatively connected to a braking unit, the robot controller being programmed to:
 operate the movable part; 
 estimate, when braking of a motion of the operated movable part is assumed to be started at a plurality of points in time, a first stop position of the movable part of the robot at each point in time; 
 access another robot to:
 obtain, when braking of a motion of an operated movable part of another robot is assumed to be started at the plurality of points in time, an estimated second stop position of the movable part of another robot based on the accessed result at each point in time, and 
 obtain an actual position of the operated movable part of another robot at each point in time; 
 
 determine, at least one of the points in time, whether the estimated first stop position of the movable part of the robot and at least one of the actual position and the obtained second stop position of the movable part of another robot are contained in the shared workspace; and 
 control the braking unit to brake the movable part when it is determined that the estimated first stop position of the movable part of the robot at the at least one of the points in time and at least one of the actual position and the obtained second stop position of the movable part of another robot at the at least one of the points in time are contained in the shared workspace. 
 
   
   
     6. A robot controller according to  claim 5  wherein the robot controller is further programmed to:
 determine whether the actual position and the obtained second stop position of the movable part of another robot are not contained in the shared workspace at a point in time after the braking; and 
 when it is determined that the actual position and the obtained second stop position of the movable part of another robot are not contained in the shared workspace at the point in time after the braking, continue the motion of the movable part of the robot from where the motion of the movable part of the robot has been stopped.